Multiple lists under single campaign- how are leads loaded?

We have multiple lists under the same campaign.
How are the leads from those lists loaded into the hopper? First matching statuses from list A, then B, then C? Or in other words are the leads in the hopper a mixture between those lists.
How are the leads from those lists loaded into the hopper? First matching statuses from list A, then B, then C? Or in other words are the leads in the hopper a mixture between those lists.